What is the ruling on money acquired from mediating the rental of a bus or car for a percentage of the paid fare?

It is permissible to take a commission from bus owners or car drivers. The first scenario is a permissible brokerage, and the broker may take their fee from one party or both parties, by agreement, provided that the party from whom the fee is taken is aware of it and that it is known at the time of the contract. As for the second scenario, it is a hire for work that is a liability (in dhimma), and it is permissible for the hired person (ajir) to hire someone to act on their behalf, unless the initial hirer stipulated that the hired person perform the work themselves, or if the work is of a nature that varies with different individuals. It is permissible to defer all or part of the fee from the contract session.